The present invention is directed to a tool bit to be inserted into a tool bit chuck of a hand-held tool used for at least one of chiseling, drilling and percussion drilling with a chucking shank having at least one axially extending locking groove closed at its axially spaced ends and at least one entrainment surface having a non-circular contour with the entrainment surface open at a free end of the chucking shank.
In a tool bit shank for a drill as described above and disclosed in DE-PS 25 51 125 there is a groove closed at its axially spaced end and having a semicircular cross-section. The spaced ends of the groove are shaped as hollow spheres and a spherically-shaped locking member engages in the groove and the locking member is guided for radial displacement in a tool bit chuck. The axial movement of the chucking shank in a tool bit chuck is limited by the locking member.
The tool bit shank has rotary entrainment grooves with entrainment faces open in the axial direction at the free end of the chucking shank. These entrainment faces cooperate with a strip or lug-shaped rotary entrainment member in the tool bit shank. The strip-shaped rotary entrainment member is fixed in the tool bit shank. In a tool bit with a small working diameter and a relatively overly large chucking shank diameter, it is necessary to effect a considerable material deformation or machining in the region of the chucking shank involving considerable expense. Such fabrication is uneconomical and cost intensive.